Evans was born in Hallowell, Maine where he grew up. He graduated from Bowdoin College where he had been a prominent member of the Peucinian Society. He moved to Gardiner, Maine and practiced law there. He was eventually elected to the Maine State Assembly and served as its speaker in 1829. In 1829, he was elected to a seat in the United States House of Representatives from Maine in a special election called after Peleg Sprague resigned to take a seat in the United States Senate. Evans served in the House from 1829 to 1841. He served as chairman of the committee on expenditures of the department of the treasury from 1829 to 1831.

In 1841, Evans resigned from the House to take a seat in the United States Senate from Maine. He served as chairman of the Senate Committee on Manufactures from 1841 to 1843, chairman of the Committee on Finance from 1841 to 1845 and chairman of the committee on territories from 1845 to 1847. Evans served in the Senate until 1847 when he was defeated in an attempt to be reelected to a second term.

Evans then practiced law in Portland, Maine and continued to be involved in politics. He served as chairman of a commission to ascertain claims against Mexico from 1849 to 1850, and served as attorney general of Maine during the 1850s. He died in Portland, Maine and is buried in the Oak Grove Cemetery in Gardiner, Maine.